特徵描述
作者
YING, SHAO-SHUN
型態特徵
Annual or perennial herbs, rarely small subshrubs, inermous, terrestrial or aquatic, usually with watery juice. Leaves radical or cauline, spirally arranged, rarely subopposite, simple to pinnately lobed; stipules absent or reduced to fine bristles or glands. Flowers usually hermaphroditic, hypogynous, in terminal or axillary racemes, sometimes solitary or several-clustered; sepals 4, free, imbricate, decussate in 2 series, rarely valvate; petals 4, free, usually clawed, alternating with the sepals; stamens mostly 6, 4-dynamous in 2 rows (the outer two stamens shortest) or 2-dynamous or 1–5 by reduction, or more than 6 by division (up to 16), filaments usually free, sometimes winged or dentate, anthers mostly sagittate, 1–2-celled, longitudinally dehiscent, nectaries variously arrayed around base of stamens; ovary syncarpous, of 2 carpels, usually bilocularly divided by a false septum (replum), style usually persistent, simple, stigma discoid, sometimes bifid. Fruit a capsule, dehiscing from below by two valves (a silique when more than 3 times as long as wide; a silicle when less than 3 times as long as wide), rarely lomentoid or indehiscent. Seeds 1-numerous, mostly exalate; embryo large; endosperm scanty or absent; cotyledons large, incumbent, accumbent or conduplicate.
屬
Genera up to 300, with more than 2,500 species of world-wide distribution, but mostly in temperate regions. Twelve genera with 22 species, one variety and one form in Taiwan.
參考文獻
Raphanus 萊菔屬
作者
YING, SHAO-SHUN
型態特徵
Annual or biennial herbs, erect or widely branching from the base, usually with tuberous thickened tap roots, glabrous or sparsely hispidulous. Leaves mostly lyrate or pinnatifid. Flowers in open-branched, bractless racemes, many, showy, white, pink, purplish or yellowish, pedicel slender; calyx erect, inner sepals somewhat saccate; petals broadly obovate, long-clawed, usually clearly veined; stamens 6, free and unappendaged; ovary 2-celled, 2–20-ovulate, stigma capitate. Fruit 2-membered, beak narrow seedless; lower segments very inconspicuous, stalk-like, upper segments cylindrical and indehiscent or constricted between the seeds and then breaking into 1-seeded segments; seeds globose; cotyledons conduplicate.
